1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
3*4882a593Smuzhiyun *
4*4882a593Smuzhiyun * Permission to use, copy, modify, and distribute this software for any
5*4882a593Smuzhiyun * purpose with or without fee is hereby granted, provided that the above
6*4882a593Smuzhiyun * copyright notice and this permission notice appear in all copies.
7*4882a593Smuzhiyun *
8*4882a593Smuzhiyun * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9*4882a593Smuzhiyun * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10*4882a593Smuzhiyun * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11*4882a593Smuzhiyun * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12*4882a593Smuzhiyun * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13*4882a593Smuzhiyun * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14*4882a593Smuzhiyun * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15*4882a593Smuzhiyun */
16*4882a593Smuzhiyun /* Test that /proc/loadavg correctly reports last pid in pid namespace. */
17*4882a593Smuzhiyun #include <errno.h>
18*4882a593Smuzhiyun #include <sched.h>
19*4882a593Smuzhiyun #include <sys/types.h>
20*4882a593Smuzhiyun #include <sys/stat.h>
21*4882a593Smuzhiyun #include <fcntl.h>
22*4882a593Smuzhiyun #include <unistd.h>
23*4882a593Smuzhiyun #include <sys/wait.h>
24*4882a593Smuzhiyun
main(void)25*4882a593Smuzhiyun int main(void)
26*4882a593Smuzhiyun {
27*4882a593Smuzhiyun pid_t pid;
28*4882a593Smuzhiyun int wstatus;
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun if (unshare(CLONE_NEWPID) == -1) {
31*4882a593Smuzhiyun if (errno == ENOSYS || errno == EPERM)
32*4882a593Smuzhiyun return 4;
33*4882a593Smuzhiyun return 1;
34*4882a593Smuzhiyun }
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun pid = fork();
37*4882a593Smuzhiyun if (pid == -1)
38*4882a593Smuzhiyun return 1;
39*4882a593Smuzhiyun if (pid == 0) {
40*4882a593Smuzhiyun char buf[128], *p;
41*4882a593Smuzhiyun int fd;
42*4882a593Smuzhiyun ssize_t rv;
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun fd = open("/proc/loadavg" , O_RDONLY);
45*4882a593Smuzhiyun if (fd == -1)
46*4882a593Smuzhiyun return 1;
47*4882a593Smuzhiyun rv = read(fd, buf, sizeof(buf));
48*4882a593Smuzhiyun if (rv < 3)
49*4882a593Smuzhiyun return 1;
50*4882a593Smuzhiyun p = buf + rv;
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun /* pid 1 */
53*4882a593Smuzhiyun if (!(p[-3] == ' ' && p[-2] == '1' && p[-1] == '\n'))
54*4882a593Smuzhiyun return 1;
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun pid = fork();
57*4882a593Smuzhiyun if (pid == -1)
58*4882a593Smuzhiyun return 1;
59*4882a593Smuzhiyun if (pid == 0)
60*4882a593Smuzhiyun return 0;
61*4882a593Smuzhiyun if (waitpid(pid, NULL, 0) == -1)
62*4882a593Smuzhiyun return 1;
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun lseek(fd, 0, SEEK_SET);
65*4882a593Smuzhiyun rv = read(fd, buf, sizeof(buf));
66*4882a593Smuzhiyun if (rv < 3)
67*4882a593Smuzhiyun return 1;
68*4882a593Smuzhiyun p = buf + rv;
69*4882a593Smuzhiyun
70*4882a593Smuzhiyun /* pid 2 */
71*4882a593Smuzhiyun if (!(p[-3] == ' ' && p[-2] == '2' && p[-1] == '\n'))
72*4882a593Smuzhiyun return 1;
73*4882a593Smuzhiyun
74*4882a593Smuzhiyun return 0;
75*4882a593Smuzhiyun }
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun if (waitpid(pid, &wstatus, 0) == -1)
78*4882a593Smuzhiyun return 1;
79*4882a593Smuzhiyun if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) == 0)
80*4882a593Smuzhiyun return 0;
81*4882a593Smuzhiyun return 1;
82*4882a593Smuzhiyun }
83